Microsoft word - november_2005.doc

Pesticide risks remain uncalculated .2Antibiotic uptake by plants from soil fertilized with animal manure.3
Antibacterial activity of soil-bound antibiotics .4Assessing the transfer of genetically modified DNA from feed to animal tissues .4
Achieving pathogen stabilization using vermicomposting .5
Welcome! This may be a short issue of our updates, but it is heavy reading. Rather depressing, in fact. More and more I wonder how it is possible that such products are even allowed
to be sold: from pesticides that are 10 x more toxic than claimed, to antibiotics that remain active in the soil and create antibiotic resistance in soil bacteria, to genetically modified food plants whose foreign bacterial and viral DNA accumulates in animal tissues to create all kinds of health problems. None of these products are necessary to create healthy plants, animals and humans – poisons can’t do that! What bizarre, twisted thought processes brought our civilization to this place?
We truly must learn to do things differently. That means we must first gain a different understanding of how things work. Hopefully the last article will help: comparing
ecosystems to organisms may be unconventional, but it is also enlightening and inspiring. Enjoy!, Heide
Source: Environmental Science & Technology On-Line, April 18, 2005
http://pubs.acs.org/subscribe/journals/esthag-w/2005/mar/science/pt_pesticide.html
Recent research has reignited an old fuss about the environmental toxicity of pesticides. In the paper, researchers point out that the active ingredients of many common pesticides consist of mirror-image structures. These isomers can have very different toxicities and degradation rates, and this fact is often missed by current EPA regulations (Proc. Nat. Acad. Sci. U.S.A. 2005,
Farmers might have to use less of many common pesticides if EPA regulations recognized the different properties of chiral active ingredients.
“In terms of regulations, nobody considers this,” says study author Jay Gan, a professor of environmental chemistry at the University of California, Riverside. “They regulate at the compound level.”
About 25% of all currently sold pesticides are chiral chemicals, and Gan says that the resulting isomers function almost like two different compounds. He examined five common insecticides, including organophosphates and pyrethroids. In each of the pesticides, one of the isomers was at least 10 times more lethal than its mirror compound to Daphnia during 96-hour aquatic
He also found that the chiral pesticide isomers degrade at different rates. In the case of two pyrethroids commonly sold to household consumers, he found that the more toxic isomers lingered much longer in the environment. In one case, when sediment samples contaminated with a pesticide were tested after one year, the more lethal isomer was found at twice the levels of the less toxic isomer. “That’s the case with these particular pesticides, but I don’t know if that’s always the case,” Gan says.
“The people in the Office of Pesticides Programs are aware of pesticide chirality and its implications for risk assessment, but they are so busy with regulatory matters concerning current and new pesticides that the chirality issue has a lower priority,” says Wayne Garrison, a research chemist with the U.S. EPA.
Scientists recognized the importance of chiral pesticides back in the late 1980s, and the issue has become more relevant in recent years. “Some registrants have taken advantage of this by enriching or purifying the pesticidally active isomer to reduce the amount of active ingredient
needed to achieve effective pest control,” says Ray McAllister, regulatory science and policy leader with CropLife America.
Although more expensive to produce, these enriched pesticides require less application and create marketing opportunities. For instance, Syngenta Crop Protection, Inc., retooled a production plant in the late 1990s to produce S-metolachlor, a formula of the old metolachlor pesticide but with a greater percentage of the active ingredient’s more effective isomer. Syngenta claims that the enhanced isomer ratio reduces the herbicide’s application rates by 35% and lowers the pesticide load to the environment by about 20 million pounds annually. Because of disagreements over registration and marketing of other metolachlor products, Syngenta later sued EPA and another pesticide manufacturer.
Garrison says that the Europeans seem to be more on top of this issue than Americans. In Switzerland, for instance, chiral pesticides belonging to one class—phenoxyalkanoic acids—can contain only the biologically active isomer. Garrison adds that the degradation of the pesticides can be even more complicated than what Gan found. The environment itself can even change which isomer degrades more quickly. In a study of the fungicide metalaxyl, researchers found that one isomer broke down more rapidly in acidic soils, while the other isomer degraded more quickly when the pH of the soil rose above 5 (Environ. Sci. Technol. 2003, 37, 2668–2674). They
concluded that the soil and the presence of bacteria that break chemicals down are important factors in determining which isomer might become more prominent over time.
Steven Bradbury, the director of the environmental fate and effects division at EPA, says that isomeric mixtures of pesticides have been a well-known issue for some time and that Gan’s paper has captured some of these concepts. “As the research advances, there are things to learn in this field,” he says.
Antibiotic Uptake by Plants from Soil Fertilized with Animal Manure
By: K. Kumara,S. C. Guptaa, S. K. Baidoob, Y. Chandera and C. J. Rosena. Department of Soil, Water, and
Climate, University of Minnesota, St. Paul, MN 55108
Source: Journal of Environmental Quality, October 12, 2005
http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0510&L=sanet-mg&T=0&F=&S=&P=9420
Antibiotics are commonly added to animal feed as supplements to promote growth of food animals. However, absorption of antibiotics in the animal gut is not complete and as a result substantial amounts of antibiotics are excreted in urine and feces that end up in manure. Manure is used worldwide not only as a source of plant nutrients but also as a source of organic matter to improve soil quality especially in organic and sustainable agriculture. Greenhouse studies were conducted to determine whether or not plants grown in manure-applied soil absorb antibiotics present in manure. The test crops were corn (Zea mays L.), green onion (Allium cepa L.), and cabbage (Brassica oleracea L. Capitata group). All three crops absorbed chlortetracycline but not tylosin. The concentrations of chlortetracycline in plant tissues were small (2–17 ng g–1 fresh weight), but these concentrations increased with increasing amount of antibiotics present in the manure. This study points out the potential
human health risks associated with consumption of fresh vegetables grown in soil amended with antibiotic laden manures. The risks may be higher for people who are allergic to antibiotics and there is also the possibility of enhanced antimicrobial resistance as a result of human consumption of these vegetables. Antibacterial activity of soil-bound antibiotics
By: Chander Y, Kumar K, Goyal SM, Gupta SC. Department of Soil, Water and Climate, 1991 Upper Buford
Circle, University of Minnesota, Saint Paul, MN 55108
Source: Journal of environmental Quality, October 12, 2005
http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0510&L=sanet-mg&T=0&F=&S=&P=15929
There is some concern that antibiotic residues in land-applied manure may promote the emergence of antibiotic resistant bacteria in the environment. The goal of this study was to determine whether or not soil bound antibiotics are still active against bacteria. The procedure involved sorbing various amounts of tetracycline or tylosin on two different textured soils (Webster clay loam [fine-loamy, mixed, superactive, mesic Typic Endoaquolls] and Hubbard loamy sand [sandy, mixed, frigid Entic Hapludolls]), incubating these soils with three different bacterial cultures (an antibiotic resistant strain of Salmonella sp. [Salmonella(R)], an antibiotic sensitive strain of Salmonella sp. [Salmonella(S)], and Escherichia coli ATCC 25922), and then enumerating the number of colony forming units relative to the control. Incubation was done under both static and dynamic conditions. Soil-adsorbed antibiotics were found to retain their antimicrobial properties since both antibiotics inhibited the growth of all three bacterial species. Averaged over all other factors, soil adsorbed antimicrobial activity was higher for Hubbard loamy sand than Webster clay loam, most likely due to higher affinity (higher clay content) of the Webster soil for antibiotics. Similarly, there was a greater decline in bacterial growth with tetracycline than tylsoin, likely due to greater amounts of soil-adsorbed tetracycline and also due to lower minimum inhibitory concentration of most bacteria for tetracycline than tylosin. The antimicrobial effect of tetracycline was also greater under dynamic than static growth conditions, possibly because agitation under dynamic growth conditions helped increase tetracycline desorption and/or increase contact between soil adsorbed tetracycline and bacteria. We conclude that even though antibiotics are tightly adsorbed by clay particles, they are still biologically active and may influence the selection of antibiotic resistant bacteria in the terrestrial environment. Assessing the Transfer of Genetically Modified DNA from Feed to Animal Tissues
By: Raffaele Mazza, Mirko Soave, Mauro Morlacchini, Gianfranco Piva and Adriano Marocco
Source: Transgenic Research Volume 14, Number 5 , October 2005
http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0510&L=sanet-mg&T=0&F=&S=&P=17064
Transgenic DNA fragments from Cry1AB maize were detected in blood, spleen, liver, kidney
and muscles of piglets fed GM maize. However, the method of isolating the cellular DNA,
though very effective, did not tell whether or not the transgenic DNA fragments were joined
to chromosomal DNA or whether they were free in the cells or their nuclei. Earlier studies from
Germany showed that bacterial viral DNA fragments from food were inserted into the
chromosomal DNA molecules of mammals . Further work is needed to detect transgenic DNA
integrated into the cells chromosomes. Finally, the report claimed that health risks from
isolated DNA have never been detected but that conclusion is wrong! Isolated bacterial DNA or
DNA fragments injected, inhaled or eaten are know to promote inflammation and
autoimmunity through the CpG stimulation of innate immunity. There are hundreds of
publications dealing with that effect. (Comment by Dr. Joe Cummins, Professor of Genetics,
In Europe, public and scientific concerns about the environmental and food safety of GM (Genetically Modified) crops overshadow the potential benefits offered by crop biotechnology to improve food quality. One of the concerns regarding the use of GM food in human and animal nutrition is the effect that newly introduced sequences may have on the organism. In this paper, we assess the potential transfer of diet-derived DNA to animal tissues after consumption of GM plants. Blood, spleen, liver, kidney and muscle tissues from piglets fed for 35 days with diets containing either GM (MON810) or a conventional maize were investigated for the presence of plant DNA. Only fragments of specific maize genes (Zein, Sh-2) could be detected with different frequencies in all the examined tissues except muscle. A small fragment of the Cry1A(b) transgene was detected in blood, liver, spleen and kidney of the animals raised with the transgenic feed. The intact Cry1A(b) gene or its minimal functional unit were never detected. Statistical analysis of the results showed no difference in recovery of positives for the presence of plant DNA between animals raised with the transgenic feed and animals raised with the conventional feed, indicating that DNA transfer may occur independently from the source and the type of the gene. From the data obtained, we consider it unlikely that the occurrence of genetic transfer associated with GM plants is higher than that from conventional plants. Achieving pathogen stabilization using vermicomposting
By: Bruce Eastman, Assistant Manager with the Orange County Environmental Protection Division, Florida
Source: BioCycle Magazine, November 1999, Page 62
http://www.jgpress.com/BCArticles/1999/11994.html
Interestingly, the ideal temperature for earthworm is about 25 degrees Celsius – and they do
not survive the “required” compost temperate of 55 degrees for so many days. More and
more literature is questioning the need for those hot composts, and interestingly – it’s
vermicompost that’s being used for commercial compost tea operations because it is
After two years of tests, a project in Florida finds that vermicomposting is effective in reducing pathogen levels in biosolids to meet Class A requirements.
Within the last decade, implementation of state and federal regulations and other local codes have changed biosolids processing in Florida. Previously, biosolids stabilization varied greatly among the state’s 3,500 to 4,000 wastewater treatment facilities. Public and privately owned wastewater treatment facilities were required to stabilize their biosolids to a minimum Class C standard for land application, with most facilities using aerobic or anaerobic digestion. Requirements for septage solids stabilization, prior to publication of the current rules and
regulations, were minimal at best. While record keeping was more organized than for septage stabilization, it was still insufficient.
With implementation of the new rules, these facilities were required to stabilize to a Class B standard. Class C was no longer satisfactory for land application. For most small facilities, this was impossible to achieve without prohibitive retrofitting and expansion, as they usually generated Class C biosolids.
Consequently, it became incumbent upon government to explore alternative methods. The Orange County (Florida)
Environmental Protection Division (OCEPD) undertook research for the potential use of earthworms as an alternative human-pathogen (pathogen) stabilization method for biosolids. Research revealed studies suggesting that vermicomposting may be effective in stabilizing pathogens. In some cases, precomposting of biosolids was done to eliminate pathogens. OCEPD staff felt, however, that the earthworms would eliminate pathogens during the vermicomposting process, making the precomposting step unnecessary. Thus the “nonthermal windrow vermicomposting” method was developed.
In 1995, a partnership was formed between OCEPD, American Earthworm Company and the city of Ocoee, Florida. The goal was to develop a Class A pathogen reduction method that is both cost-effective and meets all criteria for public health and safety set forth by the governing agencies. However, the U.S. Environmental Protection Agency (EPA) had not established standards in this area. After communicating the goals of the project and its potential benefits, the EPA developed criteria by which this project and future research could be applied to public health and safety.
Initially, a pilot study was conducted to evaluate vermiculture’s effectiveness with biosolids on a small scale. The pilot study demonstrated a noticeable reduction in the four pathogen indicators: fecal coliform, Salmonella sp., enteric virus and helminth ova in the biosolids. The next step was to begin a full-scale operation to define the project’s operational feasibility. The EPA issued a two-year experimental permit in March, 1997, with project oversight for EPA performed by the Florida Department of Environmental Protection (DEP). Standard operating procedures would be developed from the information gathered throughout the full-scale operation.
In order for vermicomposting to be considered by the EPA as an alternative methodology for Class A pathogen stabilization, the project needed to demonstrate a three-to four-fold reduction of pathogen indicators that had been spiked into the biosolids in the test and control plots. The EPA office in Cincinnati set those parameters using the reasoning that if vermiculture can demonstrate a three- to four-fold reduction in residuals that have abnormally high number of pathogen indicators, than it could be assumed that it would reduce pathogen content to the requirements of Part 503 in residuals containing normal numbers of pathogens. (EPA’s Class A pathogen reduction requirement is as follows: The density of fecal coliform in the biosolids must be less than 1,000 most probable numbers (MPN)/gram total solids (dry-weight basis) or the density of Salmonella sp. bacteria in the biosolids must be less than three MPN/four grams of total solids (dry weight-basis)).
To test whether the three-to four-fold reduction could be accomplished, a portion of the full-scale operation was utilized to house the experimental plots. A structure was constructed to protect these plots from adverse weather. Biosolids (15 to 20 percent solids) were land applied into two rows approximately six m long by 1.5 m wide by 20 cm deep, utilizing approximately 1,361 kg of biosolids each. One row was designated the test and the second was the control. These two rows were inoculated with a minimum 105 spike of three of the four pathogen indicators: fecal coliform, Salmonella sp. and enteric virus.
The test row was then seeded with E. foetida at a 1:1.5 earthworm biomass to biosolids ratio. This ratio represented the earthworms’ feeding rate for a 24-hour period. Earthworms were provided 1,361 kg of biosolids for a 14-day feeding period. Samples of both rows were collected from random locations and analyzed throughout the project.
The helminth ova portion of the experimental project was conducted at a separate time due to difficulty in acquiring the helminth ova eggs. Biosolids (15 to 20 percent solids) were land applied into two rows approximately 2.3 m long by 1.5 m wide by 23 cm deep. One row was designated as the test and the other the control. The test row was then seeded with E. foetida similar to the three pathogen tests. Florida peat, the substrate in which the earthworms were held, was spread across the test row, adding approximately 15 cm to the depth. Earthworms were provided 531 kg of biosolids for feeding for a seven-day period. Samples of both rows were randomly collected and analyzed throughout the project.
Analytical results showed that all of the pathogen indicators in the test row had a greater reduction than in the control row. EPA’s required three- to four-fold reduction was achieved in all of the pathogen indicators within 144 hours. Fecal coliform, Salmonella sp. and enteric virus achieved the EPA goal in 24 hours, 72 hours and 72 hours, respectively. The helminth ova achieved this goal within 144 hours. The helminth ova reduction times were slightly elevated compared to the previous test with the three pathogen indicators. OCEPD staff felt this occurred because of the addition of peat (substrate in which the earthworms were held) when the earthworms were added. The earthworms remained in the peat and did not immediately migrate to the biosolids. Therefore, slower reductions may have occurred because the earthworms already had a food source in the peat.
The initial baseline analysis for fecal coliforms in the test row was an average 8.5 billion MPN/one gram; the control row average was 8.3 bil ion MPN/one g. After just 24 hours, the test row samples showed an average six-fold reduction (98.70 percent) of fecal coliforms; the control row samples had a less than one-fold average reduction (20 percent). Samples collected every 24 hours for 14 days showed that reductions continued in both the test and control rows. However, the reductions in the test row were much greater and quicker than those of the control. This is due to the vermicomposting process, whereas reductions in the control row can be attributed to the natural die-off of the organisms. This is true for all of the pathogen indicators in the control row.
The initial baseline analysis for Salmonella sp. in the test row was an average 4.6 billion cells/25 ml; the control row average was 5.2 billion cells/25 ml. Samples for the Salmonella sp. analysis were collected at 72 hours and 144 hours. After 72 hours, the test row samples showed an average 13-fold reduction (99.99 percent); the control samples showed an average three-fold reduction (93.18 percent).
The initial baseline analysis for enteric virus in the test row was an average 197,000 plaque forming units (PFU)/four grams; the control row average was 173,000 PFU/four g. Samples collected for enteric virus analysis were collected at 72 hours and 144 hours. After 72 hours, the test row samples showed an average six-fold reduction (98.92 percent); the control row only had an average one-fold reduction (53.8 percent).
Viability tests done by a research team at Tulane University (headed by Dr. Robert Reimers) indicated that the helminth ova spike in the test row was 826,000 viable eggs (Ascaris sp.); the control row spike was 841,000 viable eggs (Ascaris sp.). Samples collected for helminth ova analysis were collected at 72 hours and 144 hours. After 72 hours the test row samples showed a less than one-fold average reduction (47.5 percent); the control row samples showed no reduction. After 144 hours, the test row samples showed an average six-fold reduction (98.87 percent); the control row samples showed a one-fold reduction (74.24 percent).
These results show that EPA’s required pathogen reduction in the indicator organisms was obtained, suggesting that vermicomposting can be used as an alternative method for stabilization of Class A biosolids. After pathogen stabilization has been achieved, the castings would need to be air dried to 75 percent solids to meet vector attraction reduction requirements. Drying can be done by windrowing or through a mechanical process. The latter takes one to two days (or less); however, caution should be used to prevent the destruction of the beneficial bacteria developed during vermicomposting.
All supporting documentation from this project will be submitted to the U.S. EPA for consideration as an alternative “Class A Pathogen Stabilization Methodology.”
By: Mae-Wan Hoa, , and Robert Ulanowiczb
Source: Biosystems, Volume 82, Issue 1 , October 2005
Abstract: Schrödinger [Schrödinger, E., 1944. What is Life? Cambridge University Press, Cambridge] marvelled at how the organism is able to use metabolic energy to maintain and even increase its organisation, which could not be understood in terms of classical statistical thermodynamics. Ho [Ho, M.W., 1993. The Rainbow and the Worm, The Physics of Organisms, World Scientific, Singapore; Ho, M.W., 1998a. The Rainbow and the Worm, The Physics of Organisms, 2nd (enlarged) ed., reprinted 1999, 2001, 2003 (available online from ISIS website www.i- sis.org.uk)] outlined a novel “thermodynamics of organised complexity” based on a nested dynamical structure that enables the organism to maintain its organisation and simultaneously achieve non-equilibrium and equilibrium energy transfer at maximum efficiency. This thermodynamic model of the organism is reminiscent of the dynamical structure of steady state ecosystems identified by Ulanowicz [Ulanowicz, R.E., 1983. Identifying the structure of cycling in ecosystems. Math. Biosci. 65, 210–237; Ulanowicz, R.E., 2003. Some steps towards a central theory of ecosystem dynamics. Comput. Biol. Chem. 27, 523–530]. The healthy organism excels in maintaining its organisation and keeping away from thermodynamic equilibrium – death by another name – and in reproducing and providing for future generations. In those respects, it is the ideal sustainable system. We propose therefore to explore the common features between organisms and ecosystems, to see how far we can analyse sustainable systems in agriculture, ecology and economics as organisms, and to extract indicators of the system's health or sustainability. We find that looking at sustainable systems as organisms provides fresh insights on sustainability, and offers diagnostic criteria for sustainability that reflect the system's health. In the case of ecosystems, those diagnostic criteria of health translate into properties such as biodiversity and productivity, the richness of cycles, the efficiency of energy use and minimum dissipation. In the case of economic systems, they translate into space-time differentiation or organised heterogeneity, local autonomy and sufficiency at appropriate levels, reciprocity and equality of exchange, and most of all, balancing the exploitation of natural resources – real input into the system – against the ability of the ecosystem to regenerate itself.